or decades, doctors have made a curious observation: people stricken with a particular heart or blood infection often developed colorectal cancer.

The infectious agent? A bacterial species called Streptococcus gallolyticus, known as Sg, somehow liberated from its home in the gut. So tight was this association (up to a 60 percent chance of also having colon cancer), that it became de rigueur to check lower GI tracts for signs of cancer when a person was diagnosed with an Sg heart or blood infection.

This is a STAT Plus article and you can unlock it by subscribing to STAT Plus today. It's easy! Your first 30 days are free and if you don't enjoy your subscription you can cancel any time.
Already a subscriber? Log in here.